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Posts Tagged ‘PGS – Preimplantation Genetic Screening’
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Monday, June 28th, 2010
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
More about Dr. Givens
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Since Pacific Fertility Center came into existence in November of 1999, we have been offering genetic pre-screening of IVF embryos for couples with recurrent miscar- riage, repeated IVF implantation failure and sex selection for family balancing. For most of the last decade, a technology known as Fluorescent In-Situ Hybridization, or FISH has been used to screen embryos. FISH is employed to probe a cell removed from a Day 3 embryo to determine the chromosomal makeup for anywhere from three to twelve of the cell’s 23 pairs of chromosomes. With time, we, as well as everyone else in the reproductive genetic world, came to realize the serious limitations of this technology.

First and foremost is the error rate in determining whether there are 0, 1, 2 or more signals from any one chromosome—a problem which is compounded by the more chromosomes one wishes to count from that single cell. The error rates in some studies have been reported to be as high as 50%, making PGS by FISH essentially no better than guesswork. The second issue is mosaicism. This refers to the fact that not all cells in a Day 3 embryo are identical. Some cells may be abnormal whereas the rest are normal. The normal cells can grow preferentially and create a normal embryo by implantation. However, if the cell biopsied was abnormal, that embryo would not be transferred because of obvious concern that it may result in an abnormal early pregnancy. PGS using FISH has failed to show any benefit in improving implantation and pregnancy rates in IVF. All of these factors have seriously limited the patient population for whom we have recommended this diagnostic testing.
In the last 2-3 years, as the Human Genome Project has been completed and as more DNA-related biotechnologies have emerged to evaluate human genes, these methods are being utilized to analyze human embryos. The technology now available—the ability to analyze large numbers of genetic locations on each human chromosome, and quantify that genetic material, with the previously well-established techniques to amplify a single cell’s genetic material up to hundreds of thousands of copies—has allowed PGS to take a quantum leap forward. It is now possible to more accurately analyze all 23 chromosome pairs from a single embryo; not only to determine if the correct number of copies of each chromosome is present, but also to look at single gene mutations.
At the end of 2009, Pacific Fertility Center began working with a new biotech company called Gene Security Network, located in Redwood City (genesecurity.net). This company uses gene microarray technology to analyze amplified DNA from a single cell.
It then uses microchips to analyze 30,000 genetic loci in a quantitative manner. In addition, their unique technology allows us to compare the analysis of the embryos’ cells to the parent’s chromosomes to ensure that all the genes are being properly analyzed. It does appear that the error problems that plagued FISH technology have been overcome with this new, more sophisticated, method.
In October of 2009, Dr. Conaghan and I were invited to tour the GSN laboratory and see the technology in action. We met with David Johnson, the lead scientist at GSN, who explained the cell process; from the amplification of the DNA, to arranging the chromosomes on chips, to DNA analysis, to synthesizing the data generated with the parental genetic data to come up with a full analysis of that cell’s genome. In order to process the cells between the day of embryo biopsy (Day 3) and receive the results on the day of embryo transfer (Day 5), their technicians work around the clock in shifts. GSN has a very cold, clean room to replicate the single cells into multiple copies. They cannot allow any outside contamination, not even from a single cell. They videotape the cell duplicating process so if any errors subsequently arise, they have a video record of what the laboratory technician did. We found this to be very impressive. We also saw how the chips were coated with DNA and analyzed. We were shown the sophisticated software that generates the final report detailing the genetic makeup of each embryo from the cells in which they originated. All in all, the tour gave us great confidence in the quality control and scientific integrity at GSN.
Even with this 21st century technology, we continue to biopsy Day 3 embryos because it provides us with a 48 hours window to send the cells to the lab and complete the analysis in time for transfer. However, we have not yet found a way around the problem of mosa- icism. GSN and microarray technology appears to have largely solved the resolution error problem but it can only tell us what is in the chromosomal make-up of the single cell. It cannot tell us whether or not that cell represents what is truly going on with the rest of the embryo. We are currently looking at the possibility of biopsying Day 5 embryos. The set back would result in having to freeze these embryos due to the time constraint in analyzing the genetic material in time for fresh transfer. With all of the innovation occurring daily in the genetics field, we hope that this puzzle will be resolved.
— Carolyn Givens, M.D.
Previous Fertility Flash articles about PGS:
2 Methods of Gaining Info Prior to Implantation
PGD & PGS: Why Genetic Counseling is a Prerequisite
The Benefits and Pitfalls of PGS
More On: Genetic Testing, New Innovation, PGS - Preimplantation Genetic Screening, Treatment Options Posted in Science Pulse | 1 Comment »
Friday, March 19th, 2010
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
More about Dr. Givens
· Read Other Posts |
Progress has been steady at the Center this week. From last Sunday up until this coming Saturday we will do 13 egg retrievals, 14 fresh embryo transfers, 6 frozen embryo transfers and one hysteroscopy. It looks to be a fairly typical week.
Last Saturday I attended an investigators’ meeting, along with our lab director, Dr. Joe Conaghan, for a new clinical research study that we may be undertaking with Gene Security Network (GSN). GSN is one of the pre-implantation genetic diagnosis/screening (PGD/PGS) laboratories with which we work. I really can’t discuss the details of the study at this time, as we have signed a standard non-disclosure agreement with GSN, but this will be a big study to investigate how useful PGS will be to the average IVF patient.
This leads me to the topic of today’s blog: clinical research. Although PFC is not an academic institution, we are still interested in research because this is how the field of reproductive medicine advances. In fact, since there are so many private IVF clinics, much of the research on IVF is currently being done in the private sector. We would not have the field of assisted reproduction today if it were not for clinical research and for the thousands of patients who have participated in this research to this point. I’d like our readers to know that participation in research is not taken lightly by anyone conducting the studies. As investigators, we all have to be trained in the ethical conduct of research, to make sure the risks of participation are minimized and that there is potential benefit to patients from participation. Our number one goal is still to get our patients a healthy pregnancy. We will not compromise that goal for the sake of a clinical study. The study protocols are carefully reviewed by an independent Institutional Review Board (IRB), tasked with ensuring there is no harm or undue coercion to participants. In most good studies, the design of the study includes a “control arm” and the patients who are randomized into this arm receive current standard treatment. The patients randomized to the “treatment arm” receive the treatment under investigation. It is very important that the patients in the treatment arm should be expected to be at least as successful, if not more so, than the patients in the control arm.
This year, PFC is participating in at least 4 clinical studies. Some, like our acupuncture study, are designed by PFC and are only being done at our facility. Some, like the GSN study, are being designed by the company and will be done at multiple IVF centers, then GSN will pool the data. If you are interested, please let us know. I will be posting more details very soon to our PFC website.
UPDATE: Research web page is live
More On: Clinical Trials & Studies, PGS - Preimplantation Genetic Screening Posted in What's New @ PFC? | No Comments »
Wednesday, February 10th, 2010
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
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Pacific Fertility Center and The Fertility Flash would like to invite you to a special Valentine’s Day event.
Do You Love Your Genes? Tweetup/Meetup (a Valentine’s Day event)
Thursday February 11, 2010 at 5:30pm
Pacific Fertility Center’s Education Center
55 Francisco St., Suite 550
San Francisco, California 94133 Get Directions
Please join us for genes, love, award-winning wine, chocolate, and tasty, healthy appetizers!
To view the invitation, click here
This is an in-person and virtual event for all who would like to participate and learn about the leading edge of genetics and fertility. We will also be tweeting live during the event to communicate with and connect tweeters.
Genes are an important part of life, especially for those who are struggling to conceive a child. At this event we will celebrate these building blocks of life in all forms, whether they come from biological parents, birth parents, or donors.
We will also be joined by representatives from Counsyl and the Gene Security Network (GSN) to speak about their cutting edge genetic testing technologies.
For more details on our presenters see:
Pacific Fertility Center: http://pacificfertilitycenter.com
Counsyl: http://counsyl.com
GSN: http://genesecurity.net
**
Please RSVP at rsvp@fertilitywire.com or on Facebook at http://bit.ly/bopZUZ
FertilityWire is a source of real-time fertility information and
insights founded by fertility doctors. Visit us: http://fertilitywire.com
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—Best regards from all of us at Pacific Fertility Center.
More On: Bay Area, Events, Genetic Testing, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in Conception Health, What's New @ PFC? | No Comments »
Monday, September 21st, 2009
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Joe Conaghan, PhD, HCLD is internationally recognized for his work with human embryos and brings nearly two decades of experience in human embryology to the Pacific Fertility Center.
More about Dr. Conaghan
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This summer, we are introducing a new procedure in our laboratory that will allow us to do genetic testing on embryos that have reached the blastocyst stage of development. Traditionally, embryos are biopsied when they are just 3 days old at which time they should have reached the 8-cell stage (see figure 1). The biopsied cell is sent to the genetics laboratory for testing while the remainder of the embryo continues to grow in our laboratory. The genetic testing results are received 48 hours later, when we hope that the embryo will have reached the blastocyst stage (see figure 2). Blastocysts that have passed genetic screening can be transferred or frozen for later use.
Performing the biopsy when the embryo has become a blastocyst is more technically challenging, and it allows less time for the genetics lab to do their testing. However, in a blastocyst, we are specifically able to biopsy from the part of the embryo that will become the placenta, and we can get more than 1 cell, which allows for greater accuracy in the genetic testing. Depending on how quickly the test is run, the embryo may have to be frozen while we wait for the results.
While freezing is inconvenient, it does allow time for more complex genetic testing, and for multiple tests if necessary. And, with the success of vitrification for preserving embryos (see Fertility Flash Vol. 7, Issue 3), we are confident that the frozen embryos will survive and implant at high rates when thawed.
In the next few years, we expect that the traditional methods for biopsy and genetic testing will disappear and that blastocyst biopsy will be the standard procedure. As genetic testing evolves, it will not be possible to rely on just a single cell from an embryo to get dependable results. We already know that there is genetic variability among cells in an individual embryo, a phenomenon known as mosaicism, and our new procedure will overcome this problem.
In the coming months, we will announce an exciting new partnership with a Bay Area genetic testing lab, and we will keep readers informed on our progress with genetic testing in embryos. This is an exciting field that continues to evolve.
More On: Bay Area, Blastocyst Transfer, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in What's New @ PFC? | No Comments »
Sunday, March 1st, 2009
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
· Read Other Posts |
Pacific Fertility Center is pleased to share our delivered pregnancy rates for 2007 and our preliminary clinical pregnancy rates for 2008. These outstanding pregnancy rates are made possible thanks to our team of board certified Reproductive Endocrinology and Infertility specialists, as well as, our highly trained embryologists.
Clinical pregnancy reflects the finding of a pregnancy sac in the uterus following transfer. Delivered pregnancy rate will be lower after accounting for miscarriage and pregnancy loss, particularly in older age groups.
Pacific Fertility Center Preliminary Clinical Pregnancy Rates for 2008
| Oocyte Donation |
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Fresh |
Frozen |
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Number of Cycles |
191 |
153 |
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Pregnancy Rate per transfer |
66% |
34% |
| IVF – Own Egg |
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Age |
<35 |
35-37 |
38-40 |
41-42 |
>42 |
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Number of Cycles |
180 |
166 |
174 |
119 |
58 |
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Pregnancy Rate per transfer |
51% |
46% |
42% |
31% |
15% |
| PGS/PGD – Own Egg, < 40 years of age |
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Number of Cycles |
32 |
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Clinical Pregnancy Rate per transfer |
56.3% |
| Elective Single Embryo Transfer (eSET) |
| Oocyte Donation |
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Number of Cycles |
73 |
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Clinical Pregnancy Rate per transfer |
68.5% |
|
Multiple pregnancy (identical twins) |
2 |
| IVF – Own Egg, < 40 years of age |
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Number of cycles |
41 |
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Clinical Pregnancy Rate per transfer |
51.2% |
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Multiple Pregnancy (identical twins) |
1 |
Delivered Pregnancy Rates 2007 (as reported to SART and CDC)
| Oocyte Donation – All |
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Fresh |
Frozen |
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Number of Cycles |
161 |
180 |
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Delivered Pregnancy Rate per transfer |
61.5% |
31.1% |
| IVF – Own Egg |
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Age |
<35 |
35-37 |
38-40 |
41-42 |
>42 |
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Number of Cycles |
190 |
165 |
199 |
109 |
78 |
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Delivered Pregnancy Rate per transfer |
44.1% |
42.4% |
23.5% |
22.2% |
10.9% |
More On: IVF - In Vitro Fertilization, PFC Doctors & Specialists, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening Posted in Science Pulse | No Comments »
Sunday, February 10th, 2008
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
More about Dr. Givens
· Read Other Posts |

For many people, the dream of having a family also includes the dream of having children of both sex. Since most families today are much smaller than in generations past, the odds of having two or three or even four children of the same sex is fairly high.
Throughout human history, there always has been interest in methods to sway the chances of conceiving a child of a particular sex. Today, in the 21 st century, it is quite clear that many of these sometimes bizarre and sometimes simple home remedies have no basis in fact.
There are ways to significantly shift the odds of having a child of one sex or another. Sex is conferred on an embryo by whether an X-bearing sperm (for a girl) or a Y-bearing sperm (for a boy) enters the egg. Unfortunately, despite highly publicized claims, there are no proven effective “at home” methods of sperm separation. Nor does timing of intercourse relative to ovulation affect the 50:50 sex ratio. By natural methods, the ratio remains a flip of the coin.
The only commercially available method for sperm separation that appears to be effective is the sperm sorting process available through Microsort.net. This method involves using a fluorescent DNA dye that attaches to either X or Y chromosomes. The sperm then passes through a cell sorter that separates the sperm based on the fluorescence. This method is still under FDA investigation for safety and efficacy but does appear to do a reasonable job in separating sperm, especially if the desired sex is female.
Mirosort reports a 90% success rate with separating X-bearing sperm and a 73% success rate in separating Y-bearing sperm. There have been only a few hundred babies born thus far, but there does not appear to be any increase in birth defects. Because this process is still considered “experimental,” couples wishing to participate, will have to travel to either Fairfax, Virginia (Microsort headquarters) or an affiliated clinic in Southern California for fresh sperm insemination.
Unfortunately, after Microsort processing, the number of sperm available for insemination is severely decreased. Freezing and thawing of sperm, which would allow the sample to be shipped to another location, reduces these numbers even further. Because sperm counts are so low after sorting, it is usually necessary to do in vitro fertilization with sperm injection (IVF-ICSI) to significantly improve the fertilization in the IVF laboratory. PFC is a participating site in the FDA investigation for Microsort. We have used sperm specimens that had been previously Micro-sorted for IVF-ICSI.
Researchers at UC Irvine recently published a study describing the use of lasers to “trap” the heavier and slower moving X-bearing sperm to separate it from the lighter Y-bearing sperm. In the future, this process may provide an alternative to Microsort. However, it is not yet commercially available.
Beyond the Microsort technique, the only way to improve the odds of selecting one sex over another at close to 100% accuracy is to undergo Pre-Implantation Genetic Screening (PGS). PGS uses a DNA-binding technique to determine if there are a correct number of chromosomes in the embryo at the time of IVF. To complete this screening, embryos on Day 3 of culture (5-10 cells) undergo a biopsy to remove a single cell. The rest of the embryo remains in culture in the IVF laboratory. The removed cells are analyzed for the correct number of chromosomes. Currently, PFC with its cytogenetic partner, Genetics and IVF Institue screen embryos for 3-12 chromosomes. This screening is called “aneuploidy screening.” We allow our patients to know and select the sex of their normal embryos for transfer if they so wish.
Although IVF with PGS is the most effective method for sex selection, it is certainly the most expensive and there is no absolute guarantee that the transfer of the screened embryos will result in pregnancy. A PFC physician can best discuss the odds of success, based on the woman’s age and the couple’s history of childbirth.
Many couples undergoing PGS are doing so to screen for specific genetic defects or are specifically undergoing sex selection because of their risks of having a genetic disease that only affects males (X-linked diseases).
On the other hand, PGS for elective sex selection, either for “family balancing” or even for having a first child of a particular sex poses difficult ethical issues. Just because we have the ability to choose the sex of a child, should we? What will the couple do with normal embryos of the undesired sex? At PFC, we do not encourage PGS for elective sex selection. However, if a couple is undergoing IVF and wishes to undergo aneuploidy screening, we do allow them to select to transfer embryos by sex. We encourage all patients to consider donating excess embryos of the undesired sex for adoption by other couples.
Women or couples interested in this procedure should discuss it with their Reproductive Endocrinologist. At PFC, we also refer our PGS patients for a special genetic counseling session at California Pacific Medical Center in preparation for this process.
More On: ICSI, IVF - In Vitro Fertilization, PGD - Preimplantation Genetic Diagnosis, PGS - Preimplantation Genetic Screening, Treatment Options Posted in From Us To You | No Comments »
Wednesday, June 20th, 2007
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Joe Conaghan, PhD, HCLD is internationally recognized for his work with human embryos and brings nearly two decades of experience in human embryology to the Pacific Fertility Center.
More about Dr. Conaghan
· Read Other Posts |
Question: I am an OB/GYN in the bay area and I have a patient that is interested in having a baby girl. She asked about “sperm spinning” as a method of gender selection and whether it would be useful in her situation.
Answer: Our office receives a lot of questions from patients and members of the public about sex selection. Our location in the very liberal San Francisco may be cause for the increasing demand we see in having a baby of a predetermined gender. People are also well informed about what can be achieved with modern technology, and since sex selection is a reality, there’s definite demand for it.
The procedure that you ask about, “sperm spinning” is better known in the medical and scientific communities as the “Ericsson Method”. The technology was developed by the German scientist Dr. Ronald Ericsson and has been licensed in the US and internationally since the early 1970′s. It takes advantage of the fact that sperm bearing a Y chromosome (that would make a boy) are very slightly lighter than X-chromosome bearing sperm (that would make a girl). The distribution of X and Y bearing sperm in a normal sperm sample is equal, but Ericsson’s method uses gentle centrifugation of sperm through a slightly viscous fluid to segregate the heavier (girl) sperm from the lighter (boy) sperm. Since the difference in the weight of the 2 types is so slight (about a 3% difference in amount of DNA), a perfect separation cannot be achieved. Ericsson’s website (www.childselect.com) claims a 78-85% success rate in couples seeking a boy and a 73-75% success rate for girls. At PFC, we do not endorse or recommend this method of sex selection, nor can we verify the above success rates. As far as we know, couples availing of sperm spinning are not given details of how well purified their samples are prior to using them for insemination.
A more reliable method for separating sperm in our opinion is the “Microsort” technique offered at the Genetics and IVF Institute (www.givf.com) in Fairfax, Virginia. The technique was developed originally by Dr. Lawrence Johnson at the US Department of Agriculture, and was later refined for use in humans in collaboration with GIVF. Microsort also takes advantage of the small difference in DNA content between “boy” and “girl” sperm. The sperm are dyed with a stain that binds to DNA and then an instrument called a flow cytometer can effectively separate populations of sperm based on how much dye they have incorporated. The Microsort scientists test a small aliquot of every separated sample to determine the exact enrichment that they have achieved. According to the latest figures posted on their website (microsort.net) the average enrichment for X-bearing sperm is 88% with 91% (525/574) of babies born being female. The technique is less effective for Y-bearing sperm with an average sample purity of 73% and 76% (127/152) of babies born being male. Bear in mind that the figures for babies born might be distorted since some patients may have terminated pregnancies that were not the gender that they were seeking. You may also have noticed from the GIVF data that there’s more demand for girls than boys. This is likely due at least in part to the fact that X separations work much better and therefore may be used more, but Dr. Ericsson’s website also claims a much stronger female demand even though his technology supposedly works better for boys. We do support the use of Microsort sperm here at PFC but there are limitations on the use of this technology. First, the sperm can only be separated in 2 laboratories in the US, (Fairfax and Huntington Beach in southern California), and the Microsort researchers prefer that you attend in person to give a fresh sperm sample. Second, the technology is currently only offered under an FDA approved clinical trial, and you have to be doing family balancing or trying to avoid a sex-linked disease in your family to be enrolled. For most people, unless you already have a child of a different gender from the one you are seeking, you won’t be able to participate in this FDA study.
Last, but not least is preimplantation genetic screening (PGS) that can be used to tell the sex of embryos created during in vitro fertilization (IVF). We feel that this technology is the most accurate of the sex determining strategies since there’s less than a 3% chance of a misdiagnosis. Embryos generated in an IVF cycle are subject to a biopsy procedure on the third day of growth that allows a single cell from the embryo to be analyzed to see if it has 2 X chromosomes (female) or X and a Y chromosome (male). IVF with PGS is the most accurate method for sex selection, but also the most involved and the most expensive. The Ericsson method is the easiest and the cheapest, but carries a greater risk of being inaccurate.
Joe Conaghan, PhD
More On: Bay Area, Gender Selection, IVF - In Vitro Fertilization, PGS - Preimplantation Genetic Screening, Treatment Options Posted in Ask The Experts | No Comments »
Thursday, February 1st, 2007
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
More about Dr. Givens
· Read Other Posts |

The American Society for Reproductive Medicine’s (ASRM) annual meeting was held in New Orleans. It is the largest meeting for reproductive medicine specialists and scientists in the world. From our practice, Dr.s Givens, Schriock and Conaghan attended, as well as embryologists Jean Popwell, PhD and Jennifer Andres. Also, PFC nurse Allison Chamberlaine and PFC’s Marriage and Family Therapist Peggy Orlin attended. In addition, the genetics counselor with whom we work closely, Lauri Black from California Pacific Medical Center, was an attendee and active participant.
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PFC’s embryologists attending ASRM’s research poster session Jean Popwell, PhD (left) and Jennifer Andres (right). |
Single-Embryo Transfer: Minimizing Risks & Maximizing Outcomes
Dr. Givens attended a post-graduate course entitled “Moving Toward Single-Embryo Transfer: Minimizing Risks and Maximizing Outcomes.” This two-day course dealt with a pressing issue in assisted reproduction: the high incidence of multiple gestations. With the ever-increasing success of in vitro fertilization and the significant improvement in embryo implantation rates, the incidence of twin and higher-order pregnancies has risen dramatically in this country. Many countries now regulate the maximum number of embryos that can be transferred into the uterus at one time. The course topics included a summary of optimal medication protocols, several lectures on pre-cycle evaluation and testing and embryo transfer techniques.
Oocyte Freezing, PGS & Blastocyst Embryo Transfers
On the laboratory side, there were several talks on evaluation of eggs and embryo selection techniques, embryo freezing technology, including a debate about the usefulness of pre-implantation genetic screening (chromosome analysis of embryos) embryo selection. The combination was a fascinating mixture of new ideas, refinements in current technology, as well as a welcome opportunity to network and discuss with others the latest developments in reproductive science. Topping the list of presentations in New Orleans were those concerning the continuing refinements in oocyte freezing technologies, the more selective use of preimplantation genetic testing and the ongoing scrutiny of blastocyst stage embryo transfers.
Slow-freeze vs. Vitrification
The traditional slow-freeze technology used so successfully with embryos for many years, has essentially stalled with oocyte freezing. It appears the slow-freeze technology has finally met its successor: a process called vitrification. Slow freezing has had very limited success with oocytes due to their large size, high water content and their extreme sensitivity to cryoprotective chemicals and to changes in temperature and pH.
Vitrification, a technology that cools cells so rapidly that ice does not form, has been such a success for oocyte freezing that many labs are now abandoning slow freezing altogether. Here at PFC, we have been developing protocols for oocyte vitrification throughout 2006 and are actively working on blastocyst vitrification. It was reaffirming to see that this technology has gained wide acceptance, and is showing excellent results.
Preimplantation Genetic Screening (PGS)
While vitrification is on the rise, it was interesting to see that another technology, Preimplantation Genetic Screening (PGS), was lacking in new improvements or viable alternatives. Embryos have been screened for extra or missing chromosomes for over 15 years now, but the technology has not advanced significantly over that time. It is still possible to count only 12 chromosomes in an embryo. Although the error rate per chromosome is very low, the accumulated error rate becomes significant as we count more chromosomes. PGS was “under the microscope” in several presentations in New Orleans and it appears PFC’s limited use of genetic screening is well justified. Specifically, PGS does not improve embryo selection and pregnancy rates in younger patients. Its use is limited in older patients because there are often too few embryos available to justify testing. The patients who benefit most from PGS are the younger patients who experience recurrent miscarriages. However, unless there is evidence that previous pregnancies were genetically abnormal, PGS may provide limited benefit to this group.
Blastocyst stage embryo transfers
While younger patients (those under 35) don’t benefit from PGS, they are the patient population most likely to benefit from blastocyst transfers. Culturing embryos for 5 days to the blastocyst stage, instead of the more traditional day 3 embryo transfer, is one of the main ways in which the laboratory staff can help in selecting the “best” embryo for single embryo transfer (SET) patients. Blastocyst culture techniques are well refined now and support the commitment within the community to transfer fewer embryos at one time. Furthermore, the promise of vitrification can reassure patients that their remaining embryos can be stored indefinitely when preserved at the blastocyst stage. Several presentations showed that blastocysts which were vitrified early, before their cavity (or cyst) had expanded too much, benefited most from the technology. In more advanced blastocysts, artificial reduction of the cavity gave superior results. It may not be long before vitrification is the procedure of choice for preserving all blastocysts.
2006 ASRM guidelines for numbers of embryos to transfer
The new 2006 ASRM guidelines for numbers of embryos to transfer were presented. See Tables 1 and 2 below.


The topic of whether or not federal or state legislation should regulate the maximum number of embryos to transfer was also discussed. Many people in the general public support such legislation but those of us in the field (and most patients) are opposed to the government regulating medical practice and arbitrarily setting limits on embryo transfer. In order to forestall such legislation, it is obvious that we must decrease the number of twin gestations (the number of triplet and higher-order gestations has already dramatically decreased in the last 5-7 years). At Pacific Fertility Center we have instituted a new emphasis on single embryo transfers and expect to significantly reduce the risk of multiples and achieve our goal of “optimal” pregnancy outcomes. (See From Us to You in this issue for a discussion of our 2006 statistics and please see Conception Health in this issue for a discussion of why it is important to try to achieve single baby conceptions.
– Carolyn Givens, MD and Joe Conaghan, PhD
More On: Clinical Trials & Studies, Egg Freezing, Embryo Freezing, IVF - In Vitro Fertilization, Lab, New Innovation, PGS - Preimplantation Genetic Screening, What's New @ PFC? Posted in Science Pulse | Comments Off
Thursday, July 27th, 2006
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The PFC Staff, as a unified team, is guided by the highest ethical standards. We provide our patients with the best quality, individualized, compassionate fertility care.
More about The PFC Staff
· Read Other Posts |
Here are some images from the different techniques that can be used for gender selection

To read more about this process, see our Ask The Experts post
More On: Gender Selection, Genetic Testing, Lab, PGS - Preimplantation Genetic Screening Posted in Photo Gallery | No Comments »
Friday, July 7th, 2006
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Dr. Carolyn Givens worked with thousands of in vitro fertilization patients over the last decade using a combination of attentive, personal care and advanced medical technology.
More about Dr. Givens
· Read Other Posts |

Pacific Fertility Center Team
Left to Right: Front: Philip Chenette, MD, Isabelle Ryan, MD, Carolyn Givens, MD
Back: Joe Conaghan, PhD, Carl Herbert, MD, Eldon Schriock, MD
Question: My husband and I have two boys and want to have a girl.
What are our options?
Answer: Gender selection is a complicated and difficult issue. Ethics aside, there really are only two proven methods. The first is a technique of sorting sperm cells called Microsort. If there is a healthy number of motile sperm present (no significant male infertility), the husband can fly to Southern California to the Microsort lab and have the sperm sorted. That sperm can then be used to inseminate the wife at Huntington Reproductive Center in Laguna Hills or can be frozen and shipped back to PFC for use in IVF. Because the technique results in such poor recovery of sperm, insemination may take several tries. This is why most of our patients will use the sperm in conjunction with IVF, in which case we can inseminate by single sperm injection (ICSI) several of the wife’s eggs, producing and then transferring embryos back to the uterus, and giving the couple a better chance of success. The sperm sorting method is much more efficient if the gender desired is female (see Microsort Facts below). We receive a report from Microsort about the estimated percentage of sperm that are X-bearing (female) vs. Y-bearing (male). Usually, for a female, that is about 85% and most couples interested in a girl are comfortable with those odds. For a male, the odds are lower (about 73%) and therefore, if a boy is really desired, most couples look to PGS (Pre-Implantation Genetic Screening).
With PGS, the patients undergo IVF with ICSI to create the embryos, and when the resulting embryos have 5-8 cells, a single cell is removed and analyzed for a number of chromosomes, including X and Y. If the couple wishes to transfer only the embryos of one gender, they will have to decide what to do with the remaining embryos. The technique is close to 93% accurate, which is a huge advantage over Microsort if male gender is desired. However, our most recent statistics with PGS indicate implantation rates tend to be lower. We do suspect that the procedure of removing a cell from the embryo may be decreasing the chances of successful implantation.
There are many more complex issues involved with PGS so we require our patients considering this process to meet with a genetics counselor (we work with the Perinatal Genetics program at California Pacific Medical Center for this counseling) to discuss the implications of undergoing this process in more depth.
– Carolyn Givens, M.D.
- Microsort Facts • Sperm sorting technique
- Two locations: Virginia and Southern California
- Must be younger than 40 years old (or using egg donor)
- Must be for Family Balancing (not first child)
- Low % of sperm recovered
- Efficiency for a girl is about 85%
- Efficiency for a boy is about 73%
For more info, visit the website: www.microsort.net
More On: Gender Selection, Lab, PGS - Preimplantation Genetic Screening Posted in Ask The Experts | No Comments »
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| Welcome to InfertilityDoctor.com, blog of Pacific Fertility Center. Located in San Francisco, California, PFC is the leading Bay Area infertility clinic specializing in PGD: preimplantation genetic diagnosis, IVF: in vitro fertilization, egg donor programs, embryo freezing, ICSI & IVF as well as other advanced female and male infertility treatment solutions. Our office is conveniently located near the Bay Bridge and is accessible to those traveling from Bay Area communities such as the East Bay (Berkeley, Oakland, and Walnut Creek), North Bay (Marin and Santa Rosa), Peninsula (San Mateo), and South Bay (San Jose). Our office is also less than an hour-and-a-half from Northern California communities such as Sacramento and Stockton. |
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